Sunnyvale is a city in Santa Clara County, California, United States. It is one of the major cities that make up the Silicon Valley. As of the 2000 census, the city population was 131,760. The city is bordered by the San Francisco Bay and portions of San Jose to the north, Moffett Federal Airfield to the northwest, Mountain View to the west, Los Altos to the southwest, Cupertino to the south, and Santa Clara to the east. It lies along the historic El Camino Real and Highway 101. As part of the Silicon Valley, Sunnyvale is headquarters to several high-tech companies such as Maxim Integrated Products, Juniper Networks, Palm, Inc. , AMD, NetApp, Spansion, Yahoo!, Mirapoint, and Ariba. Sunnyvale is also home to several aerospace/defense companies; Lockheed Martin has a major facility in Sunnyvale, and Honeywell, Northrop Grumman Electronic Systems - Marine Systems (location of the Hendy Iron Works Museum), and Spirent Communications also have offices in Sunnyvale. Sunnyvale is also the home to Onizuka Air Force Station, where its main building, locally known as the Blue Cube, is its most prominent feature. The base, named for the deceased Space Shuttle Challenger astronaut Ellison Onizuka, is the primary artificial satellite control facility of the United States armed forces. Sunnyvale is one of the few U.S. cities to have a single unified Department of Public Safety, where all personnel are trained as firefighters, police officers, and EMTs, so they can respond to an emergency in any of the three roles. Library services for the city are provided by the Sunnyvale Public Library, located at the Sunnyvale Civic Center.